全文获取类型
收费全文 | 1252篇 |
免费 | 12篇 |
国内免费 | 15篇 |
专业分类
安全科学 | 47篇 |
废物处理 | 55篇 |
环保管理 | 187篇 |
综合类 | 228篇 |
基础理论 | 259篇 |
环境理论 | 2篇 |
污染及防治 | 311篇 |
评价与监测 | 105篇 |
社会与环境 | 76篇 |
灾害及防治 | 9篇 |
出版年
2023年 | 15篇 |
2022年 | 25篇 |
2021年 | 28篇 |
2020年 | 17篇 |
2019年 | 21篇 |
2018年 | 33篇 |
2017年 | 28篇 |
2016年 | 33篇 |
2015年 | 30篇 |
2014年 | 43篇 |
2013年 | 60篇 |
2012年 | 62篇 |
2011年 | 74篇 |
2010年 | 51篇 |
2009年 | 70篇 |
2008年 | 60篇 |
2007年 | 80篇 |
2006年 | 52篇 |
2005年 | 52篇 |
2004年 | 57篇 |
2003年 | 41篇 |
2002年 | 46篇 |
2001年 | 34篇 |
2000年 | 19篇 |
1999年 | 16篇 |
1998年 | 22篇 |
1997年 | 13篇 |
1996年 | 18篇 |
1995年 | 18篇 |
1994年 | 13篇 |
1993年 | 9篇 |
1992年 | 13篇 |
1991年 | 8篇 |
1990年 | 15篇 |
1989年 | 7篇 |
1988年 | 8篇 |
1987年 | 4篇 |
1986年 | 10篇 |
1985年 | 9篇 |
1984年 | 11篇 |
1983年 | 9篇 |
1982年 | 8篇 |
1981年 | 3篇 |
1979年 | 3篇 |
1974年 | 3篇 |
1973年 | 2篇 |
1972年 | 4篇 |
1969年 | 2篇 |
1968年 | 3篇 |
1965年 | 2篇 |
排序方式: 共有1279条查询结果,搜索用时 390 毫秒
761.
R. Terry Bowyer Janet L. Rachlow Kelley M. Stewart Victor Van Ballenberghe 《Behavioral ecology and sociobiology》2011,65(12):2251-2260
Evidence of female fomentation of male–male aggression as a mechanism of mate choice is rare, especially in mammals. Female
choice of mates in polygynous species may be masked by intense male competition or by males attempting to restrict female
choice. We studied protest moans of female Alaskan moose Alces alces gigas in interior Alaska, USA, from 1987 to 1990, to determine if moans incited male–male aggression. Alaskan moose exhibit a mating
system in which one dominant male (the harem master) herds, defends, courts, and attempts to mate with females in his harem.
Protest moans were given by females only in response to courtship. We hypothesized that if protest moans were related to females
reducing harassment and exercising mate choice, females should give protest moans more frequently when courted by small males
and less often when courted by large males, and that rates of male–male aggression would be elevated following protest moans.
Harems were composed of one large male, with a mean of 4.4 females (median = 3 females); 10% of 132 harems included ≥10 females.
The temporal pattern of protest moans from late August through November was associated with, but tended to lag behind, mating
behavior. The rate of protest moans given by females decreased with increasing size of males courting them. Male–male aggression
was significantly less during periods without protest moans than during periods in which protest moans occurred. These results
indicate that female moose gave protest moans to reduce harassment by smaller males, and assure a mating opportunity with
the most dominant male. Such a subtle mechanism of indirect mate choice by females may occur in other vertebrates in which
choice is limited by a mating system in which male–male combat and male dominance over females reduces opportunities for female
choice. The importance of female choice may be undervalued in studies of sexual selection in mammals. 相似文献
762.
Can A Van Renterghem T Rademaker M Dauwe S Thomas P De Baets B Botteldooren D 《Journal of environmental monitoring : JEM》2011,13(10):2710-2719
Requirements for static (prediction of L(den) and diurnal averaged noise pattern) and dynamic (prediction of 15 min and 60 min evolution of L(Aeq) and statistical levels L(A90,)L(A50) and L(A10)) noise level monitoring are investigated in this paper. Noise levels are measured for 72 consecutive days at 5 neighboring streets in an inner-city noise measurement network in Gent, Flanders, Belgium. We present a method to make predictions based on a fixed monitoring station, combined with short-term sampling at temporary stations. It is shown that relying on a fixed station improves the estimation of L(den) at other locations, and allows for the reduction of the number of samples needed and their duration; L(den) is estimated with an error that does not exceed 1.5 dB(A) to 3.4 dB(A) according to the location, for 90% of the 3 × 15 min samples. Also the diurnal averaged noise pattern can be estimated with a good accuracy in this way. It was shown that there is an optimal location for the fixed station which can be found by short-term measurements only. Short-term level predictions were shown to be more difficult; 7 day samples were needed to build models able to estimate the evolution of L(Aeq,60min) with a RMSE ranging between 1.4 dB(A) and 3.7 dB(A). These higher values can be explained by the very pronounced short-term variations appearing in typical streets, which are not correlated between locations. On the other hand, moderately accurate predictions can be achieved, even based on short-term sampling (a 3 × 15 minute sampling duration seems to be sufficient for many of the accuracy goals set related to static and dynamic monitoring). Finally, the method proposed also allows for the prediction of the evolution of statistical indicators. 相似文献
763.
Van Renterghem T Thomas P Dominguez F Dauwe S Touhafi A Dhoedt B Botteldooren D 《Journal of environmental monitoring : JEM》2011,13(3):544-552
The massive production of microphones for consumer electronics, and the shift from dedicated processing hardware to PC-based systems, opens the way to build affordable, extensive noise measurement networks. Applications include e.g. noise limit and urban soundscape monitoring, and validation of calculated noise maps. Microphones are the critical components of such a network. Therefore, in a first step, some basic characteristics of 8 microphones, distributed over a wide range of price classes, were measured in a standardized way in an anechoic chamber. In a next step, a thorough evaluation was made of the ability of these microphones to be used for environmental noise monitoring. This was done during a continuous, half-year lasting outdoor experiment, characterized by a wide variety of meteorological conditions. While some microphones failed during the course of this test, it was shown that it is possible to identify cheap microphones that highly correlate to the reference microphone during the full test period. When the deviations are expressed in total A-weighted (road traffic) noise levels, values of less than 1 dBA are obtained, in excess to the deviation amongst reference microphones themselves. 相似文献
764.
A scaled-up conversion process of fish waste to liquid fertilizer was performed in a 5 L ribbon-type reactor. Biodegradation was performed by inoculation of autoclaved fish waste with 5.84 × 10(5) CFU mL(-1) of mixed microorganisms for 96 h. As a result, the pH changed from 6.92 to 5.72, the cell number reached 7.28 × 10(5) CFU mL(-1), and approximately 430 g (28.3%) of fish waste was degraded. Analyses indicated that the 96 h culture of inoculated fish waste possessed comparable fertilizing ability to commercial fertilizers in hydroponic culture with amino acid contents of 6.91 g 100 g(-1). Therefore, the scaled-up production achieved a more satisfactory fish waste degradation rate (3.61 g h(-1)) than the flask-scale production (0.24 g h(-1)). The biodegraded broth of fish waste at room temperature did not undergo putrefaction for 6 months due to the addition of 1% lactate. 相似文献
765.
Tran Thuan Van Nguyen Duyen Thi Cam Kumar Ponnusamy Senthil Din Azam Taufik Mohd Jalil Aishah Abdul Vo Dai-Viet N. 《Environmental Chemistry Letters》2022,20(2):1309-1331
Environmental Chemistry Letters - Pollution and diseases such as the coronavirus pandemic (COVID-19) are major issues that may be solved partly by nanotechnology. Here we review the synthesis of... 相似文献
766.
Dang Tran Ngoc Vy Nguyen Thi Tuong Thuong Do Thi Hoai Phung Dung Van Dung Do Le An Pham 《Environmental science and pollution research international》2022,29(39):59094-59103
Environmental Science and Pollution Research - Vietnam is highly vulnerable to climate change-related extreme weather events such as heatwaves. This study assesses the association between heatwaves... 相似文献
767.
Yousefzadeh Ameneh Maleki Afshin Athar Saeed Dehestani Darvishi Ebrahim Ahmadi Manochehr Mohammadi Ebrahim Tang Van Tai Kalmarzi Rasoul Nassiri Kashefi Hajar 《Environmental science and pollution research international》2022,29(10):14143-14157
Environmental Science and Pollution Research - Exposure to bioaerosols in the air of hospitals is associated with a wide range of adverse health effects due to the presence of airborne... 相似文献
768.
随着新的教育、教学技术的不断涌现和新的教学模式的提出,传统的实验教学模式已经不能满足现代素质教育的要求,急需新的更为先进的教学模式来提高实验教学的效果。在此背景下,笔者通过研究探究式教学模式,并将此模式应用到大学物理实验教学中,取得了良好的效果。 相似文献
769.
Frans J. Los Cardi van den Berg Hajo I. J. Wildschut Helen Brandenburg Nicolette S. den Hollander Ernst M. Schoonderwaldt Leen Pijpers Robert Jan H. Galjaard Diane Van Opstal 《黑龙江环境通报》2001,21(13):1150-1158
First-trimester chorionic villus sampling has not reached the popularity of second-trimester amniocentesis in prenatal cytogenetic diagnosis, in contrast to initial expectations. We investigated whether a difference inthe diagnostic performances of cytogenetic investigation in amniotic fluid (AF) cells and chorionic villi in favour of AF-cells might justify this. Diagnostic performance was measured as laboratory failure rate, karyotype quality (G-band score, rate of follow-up samples, rate of wrong diagnoses), and karyotype representativity (rate of follow-up samples, rate of wrong diagnoses). From 1993–1999, 11 883 AF-samples were investigated (AF-cells). In chorionic villi, short term culture preparations solely were karyotyped from 1993–1996 (n=3499) (STC-villi), short and long-term culture preparations simultaneously provided a sufficient amount of tissue being available from 1997 onwards (n=1829) ((STC+LTC)-villi). Laboratory failure rates were the same after amniocentesis (0.40%) and chorionic villus sampling (0.50%). G-band scores (mean±SD) were equal in AF-cells (373±38.1) and LTC-villi (364±32.6) but significantly lower in STC-villi (311±34.6) (p=0.001). Follow-up sampling rates because of quality reasons were the same in AF-cells (0.14%), STC- villi (0.13%) and (STC+LTC)-villi (0.11%). Two wrong diagnoses turned up among AF-cells. Follow-up sampling rates because of representativity reasons differed significantly between AF-cells (0.10%), (STC+LTC)-villi (1.31%), and STC-villi (1.99%) (p<0.001). However, the ratios of the total numbers of follow-up samples and uncertain or abnormal cytogenetic results in STC, and (STC+LTC)-villi at cytogenetic risks ⩾3% (0.132 and 0.160, respectively) were equal to that in AF-cells at risks <3% (0.155). Two wrong diagnoses were made in STC-villi. Diagnostic performance improved in the rank order of STC-villi, (STC+LTC)-villi and AF-cells. At cytogenetic risks ⩾3%, (STC+LTC)-villi showed a diagnostic performance equal to that in AF-cells. This might justify a selective use of chorionic villus sampling. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
770.
M. A. Van Buren W. E. Watt J. Marsalek 《Journal of Environmental Planning and Management》1997,40(1):5-18
A methodologyis presented for assessing the pollution control performance of an on-stream stormwater pond, and the application of this methodology to a specific facility in Kingston, Ontario, Canada is documented. This assessment is based on constituent mass balances for both baseflow and event conditions. Results on removal rates are provided for selected dissolved constituents, nutrients, suspended solids, metals and organic contaminants. In summary, dissolved constituents exhibit zero removal for baseflow periods and positive removal for events; nutrients and suspended solids exhibit negative removal for baseflow periods and positive removal for events; and metals and organics exhibit positive removal for both baseflow periods and events. Constituent removal appears to be controlled mainly by physical processes (sedimentation), and the uncertainties associated with the estimates of constituent loads are quantified. 相似文献